Horizontal Transmission of Parotitis Vaccine Strain From Vaccinated to Close Contacts

Abstract

Aim. A controlled study was carried out regarding horizontal transmission of the vaccine strain of parotitic virus (PV). Materials and methods. 20 couples took part in the study. Monitoring of both spouses was carried out for 42 days after a single vaccination of one of them, levels of specific IgM and IgG in sera and virus-neutralizing IgG in sera and saliva were studied in dynamics, PV RNA was also determined in sera and saliva samples. Amplified fragments of F, SH, NP and HN genes of PV were sequenced. Results. Transfer of PV vaccine strain was registered in all the couples except for one. Except a single contact spouse, all the rest demonstrated formation of a specific immune response. At month 4 of the observation, group of vaccinated spouses differed significantly from a group of contact spouses only by total content of specific IgG and their avidity. Conclusion. Horizontal transmission of PV strain was demonstrated in couples after vaccination of one of the spouses and resulted in formation of specific immunity in 95% of contact individuals.